1 /* -*- mode: c; c-basic-offset: 8; -*- 2 * vim: noexpandtab sw=8 ts=8 sts=0: 3 * 4 * dlmdomain.c 5 * 6 * defines domain join / leave apis 7 * 8 * Copyright (C) 2004 Oracle. All rights reserved. 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public 12 * License as published by the Free Software Foundation; either 13 * version 2 of the License, or (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 18 * General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public 21 * License along with this program; if not, write to the 22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 23 * Boston, MA 021110-1307, USA. 24 * 25 */ 26 27 #include <linux/module.h> 28 #include <linux/types.h> 29 #include <linux/slab.h> 30 #include <linux/highmem.h> 31 #include <linux/utsname.h> 32 #include <linux/init.h> 33 #include <linux/spinlock.h> 34 #include <linux/delay.h> 35 #include <linux/err.h> 36 37 #include "cluster/heartbeat.h" 38 #include "cluster/nodemanager.h" 39 #include "cluster/tcp.h" 40 41 #include "dlmapi.h" 42 #include "dlmcommon.h" 43 44 #include "dlmdebug.h" 45 #include "dlmdomain.h" 46 47 #include "dlmver.h" 48 49 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_DOMAIN) 50 #include "cluster/masklog.h" 51 52 /* 53 * 54 * spinlock lock ordering: if multiple locks are needed, obey this ordering: 55 * dlm_domain_lock 56 * struct dlm_ctxt->spinlock 57 * struct dlm_lock_resource->spinlock 58 * struct dlm_ctxt->master_lock 59 * struct dlm_ctxt->ast_lock 60 * dlm_master_list_entry->spinlock 61 * dlm_lock->spinlock 62 * 63 */ 64 65 spinlock_t dlm_domain_lock = SPIN_LOCK_UNLOCKED; 66 LIST_HEAD(dlm_domains); 67 static DECLARE_WAIT_QUEUE_HEAD(dlm_domain_events); 68 69 #define DLM_DOMAIN_BACKOFF_MS 200 70 71 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data); 72 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data); 73 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data); 74 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data); 75 76 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm); 77 78 void __dlm_unhash_lockres(struct dlm_lock_resource *lockres) 79 { 80 hlist_del_init(&lockres->hash_node); 81 dlm_lockres_put(lockres); 82 } 83 84 void __dlm_insert_lockres(struct dlm_ctxt *dlm, 85 struct dlm_lock_resource *res) 86 { 87 struct hlist_head *bucket; 88 struct qstr *q; 89 90 assert_spin_locked(&dlm->spinlock); 91 92 q = &res->lockname; 93 q->hash = full_name_hash(q->name, q->len); 94 bucket = &(dlm->lockres_hash[q->hash % DLM_HASH_BUCKETS]); 95 96 /* get a reference for our hashtable */ 97 dlm_lockres_get(res); 98 99 hlist_add_head(&res->hash_node, bucket); 100 } 101 102 struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm, 103 const char *name, 104 unsigned int len) 105 { 106 unsigned int hash; 107 struct hlist_node *iter; 108 struct dlm_lock_resource *tmpres=NULL; 109 struct hlist_head *bucket; 110 111 mlog_entry("%.*s\n", len, name); 112 113 assert_spin_locked(&dlm->spinlock); 114 115 hash = full_name_hash(name, len); 116 117 bucket = &(dlm->lockres_hash[hash % DLM_HASH_BUCKETS]); 118 119 /* check for pre-existing lock */ 120 hlist_for_each(iter, bucket) { 121 tmpres = hlist_entry(iter, struct dlm_lock_resource, hash_node); 122 if (tmpres->lockname.len == len && 123 memcmp(tmpres->lockname.name, name, len) == 0) { 124 dlm_lockres_get(tmpres); 125 break; 126 } 127 128 tmpres = NULL; 129 } 130 return tmpres; 131 } 132 133 struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm, 134 const char *name, 135 unsigned int len) 136 { 137 struct dlm_lock_resource *res; 138 139 spin_lock(&dlm->spinlock); 140 res = __dlm_lookup_lockres(dlm, name, len); 141 spin_unlock(&dlm->spinlock); 142 return res; 143 } 144 145 static struct dlm_ctxt * __dlm_lookup_domain_full(const char *domain, int len) 146 { 147 struct dlm_ctxt *tmp = NULL; 148 struct list_head *iter; 149 150 assert_spin_locked(&dlm_domain_lock); 151 152 /* tmp->name here is always NULL terminated, 153 * but domain may not be! */ 154 list_for_each(iter, &dlm_domains) { 155 tmp = list_entry (iter, struct dlm_ctxt, list); 156 if (strlen(tmp->name) == len && 157 memcmp(tmp->name, domain, len)==0) 158 break; 159 tmp = NULL; 160 } 161 162 return tmp; 163 } 164 165 /* For null terminated domain strings ONLY */ 166 static struct dlm_ctxt * __dlm_lookup_domain(const char *domain) 167 { 168 assert_spin_locked(&dlm_domain_lock); 169 170 return __dlm_lookup_domain_full(domain, strlen(domain)); 171 } 172 173 174 /* returns true on one of two conditions: 175 * 1) the domain does not exist 176 * 2) the domain exists and it's state is "joined" */ 177 static int dlm_wait_on_domain_helper(const char *domain) 178 { 179 int ret = 0; 180 struct dlm_ctxt *tmp = NULL; 181 182 spin_lock(&dlm_domain_lock); 183 184 tmp = __dlm_lookup_domain(domain); 185 if (!tmp) 186 ret = 1; 187 else if (tmp->dlm_state == DLM_CTXT_JOINED) 188 ret = 1; 189 190 spin_unlock(&dlm_domain_lock); 191 return ret; 192 } 193 194 static void dlm_free_ctxt_mem(struct dlm_ctxt *dlm) 195 { 196 if (dlm->lockres_hash) 197 free_page((unsigned long) dlm->lockres_hash); 198 199 if (dlm->name) 200 kfree(dlm->name); 201 202 kfree(dlm); 203 } 204 205 /* A little strange - this function will be called while holding 206 * dlm_domain_lock and is expected to be holding it on the way out. We 207 * will however drop and reacquire it multiple times */ 208 static void dlm_ctxt_release(struct kref *kref) 209 { 210 struct dlm_ctxt *dlm; 211 212 dlm = container_of(kref, struct dlm_ctxt, dlm_refs); 213 214 BUG_ON(dlm->num_joins); 215 BUG_ON(dlm->dlm_state == DLM_CTXT_JOINED); 216 217 /* we may still be in the list if we hit an error during join. */ 218 list_del_init(&dlm->list); 219 220 spin_unlock(&dlm_domain_lock); 221 222 mlog(0, "freeing memory from domain %s\n", dlm->name); 223 224 wake_up(&dlm_domain_events); 225 226 dlm_free_ctxt_mem(dlm); 227 228 spin_lock(&dlm_domain_lock); 229 } 230 231 void dlm_put(struct dlm_ctxt *dlm) 232 { 233 spin_lock(&dlm_domain_lock); 234 kref_put(&dlm->dlm_refs, dlm_ctxt_release); 235 spin_unlock(&dlm_domain_lock); 236 } 237 238 static void __dlm_get(struct dlm_ctxt *dlm) 239 { 240 kref_get(&dlm->dlm_refs); 241 } 242 243 /* given a questionable reference to a dlm object, gets a reference if 244 * it can find it in the list, otherwise returns NULL in which case 245 * you shouldn't trust your pointer. */ 246 struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm) 247 { 248 struct list_head *iter; 249 struct dlm_ctxt *target = NULL; 250 251 spin_lock(&dlm_domain_lock); 252 253 list_for_each(iter, &dlm_domains) { 254 target = list_entry (iter, struct dlm_ctxt, list); 255 256 if (target == dlm) { 257 __dlm_get(target); 258 break; 259 } 260 261 target = NULL; 262 } 263 264 spin_unlock(&dlm_domain_lock); 265 266 return target; 267 } 268 269 int dlm_domain_fully_joined(struct dlm_ctxt *dlm) 270 { 271 int ret; 272 273 spin_lock(&dlm_domain_lock); 274 ret = (dlm->dlm_state == DLM_CTXT_JOINED) || 275 (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN); 276 spin_unlock(&dlm_domain_lock); 277 278 return ret; 279 } 280 281 static void dlm_complete_dlm_shutdown(struct dlm_ctxt *dlm) 282 { 283 dlm_unregister_domain_handlers(dlm); 284 dlm_complete_thread(dlm); 285 dlm_complete_recovery_thread(dlm); 286 287 /* We've left the domain. Now we can take ourselves out of the 288 * list and allow the kref stuff to help us free the 289 * memory. */ 290 spin_lock(&dlm_domain_lock); 291 list_del_init(&dlm->list); 292 spin_unlock(&dlm_domain_lock); 293 294 /* Wake up anyone waiting for us to remove this domain */ 295 wake_up(&dlm_domain_events); 296 } 297 298 static void dlm_migrate_all_locks(struct dlm_ctxt *dlm) 299 { 300 int i; 301 struct dlm_lock_resource *res; 302 303 mlog(0, "Migrating locks from domain %s\n", dlm->name); 304 restart: 305 spin_lock(&dlm->spinlock); 306 for (i = 0; i < DLM_HASH_BUCKETS; i++) { 307 while (!hlist_empty(&dlm->lockres_hash[i])) { 308 res = hlist_entry(dlm->lockres_hash[i].first, 309 struct dlm_lock_resource, hash_node); 310 /* need reference when manually grabbing lockres */ 311 dlm_lockres_get(res); 312 /* this should unhash the lockres 313 * and exit with dlm->spinlock */ 314 mlog(0, "purging res=%p\n", res); 315 if (dlm_lockres_is_dirty(dlm, res)) { 316 /* HACK! this should absolutely go. 317 * need to figure out why some empty 318 * lockreses are still marked dirty */ 319 mlog(ML_ERROR, "lockres %.*s dirty!\n", 320 res->lockname.len, res->lockname.name); 321 322 spin_unlock(&dlm->spinlock); 323 dlm_kick_thread(dlm, res); 324 wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res)); 325 dlm_lockres_put(res); 326 goto restart; 327 } 328 dlm_purge_lockres(dlm, res); 329 dlm_lockres_put(res); 330 } 331 } 332 spin_unlock(&dlm->spinlock); 333 334 mlog(0, "DONE Migrating locks from domain %s\n", dlm->name); 335 } 336 337 static int dlm_no_joining_node(struct dlm_ctxt *dlm) 338 { 339 int ret; 340 341 spin_lock(&dlm->spinlock); 342 ret = dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN; 343 spin_unlock(&dlm->spinlock); 344 345 return ret; 346 } 347 348 static void dlm_mark_domain_leaving(struct dlm_ctxt *dlm) 349 { 350 /* Yikes, a double spinlock! I need domain_lock for the dlm 351 * state and the dlm spinlock for join state... Sorry! */ 352 again: 353 spin_lock(&dlm_domain_lock); 354 spin_lock(&dlm->spinlock); 355 356 if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) { 357 mlog(0, "Node %d is joining, we wait on it.\n", 358 dlm->joining_node); 359 spin_unlock(&dlm->spinlock); 360 spin_unlock(&dlm_domain_lock); 361 362 wait_event(dlm->dlm_join_events, dlm_no_joining_node(dlm)); 363 goto again; 364 } 365 366 dlm->dlm_state = DLM_CTXT_LEAVING; 367 spin_unlock(&dlm->spinlock); 368 spin_unlock(&dlm_domain_lock); 369 } 370 371 static void __dlm_print_nodes(struct dlm_ctxt *dlm) 372 { 373 int node = -1; 374 375 assert_spin_locked(&dlm->spinlock); 376 377 mlog(ML_NOTICE, "Nodes in my domain (\"%s\"):\n", dlm->name); 378 379 while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES, 380 node + 1)) < O2NM_MAX_NODES) { 381 mlog(ML_NOTICE, " node %d\n", node); 382 } 383 } 384 385 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data) 386 { 387 struct dlm_ctxt *dlm = data; 388 unsigned int node; 389 struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf; 390 391 mlog_entry("%p %u %p", msg, len, data); 392 393 if (!dlm_grab(dlm)) 394 return 0; 395 396 node = exit_msg->node_idx; 397 398 mlog(0, "Node %u leaves domain %s\n", node, dlm->name); 399 400 spin_lock(&dlm->spinlock); 401 clear_bit(node, dlm->domain_map); 402 __dlm_print_nodes(dlm); 403 404 /* notify anything attached to the heartbeat events */ 405 dlm_hb_event_notify_attached(dlm, node, 0); 406 407 spin_unlock(&dlm->spinlock); 408 409 dlm_put(dlm); 410 411 return 0; 412 } 413 414 static int dlm_send_one_domain_exit(struct dlm_ctxt *dlm, 415 unsigned int node) 416 { 417 int status; 418 struct dlm_exit_domain leave_msg; 419 420 mlog(0, "Asking node %u if we can leave the domain %s me = %u\n", 421 node, dlm->name, dlm->node_num); 422 423 memset(&leave_msg, 0, sizeof(leave_msg)); 424 leave_msg.node_idx = dlm->node_num; 425 426 status = o2net_send_message(DLM_EXIT_DOMAIN_MSG, dlm->key, 427 &leave_msg, sizeof(leave_msg), node, 428 NULL); 429 430 mlog(0, "status return %d from o2net_send_message\n", status); 431 432 return status; 433 } 434 435 436 static void dlm_leave_domain(struct dlm_ctxt *dlm) 437 { 438 int node, clear_node, status; 439 440 /* At this point we've migrated away all our locks and won't 441 * accept mastership of new ones. The dlm is responsible for 442 * almost nothing now. We make sure not to confuse any joining 443 * nodes and then commence shutdown procedure. */ 444 445 spin_lock(&dlm->spinlock); 446 /* Clear ourselves from the domain map */ 447 clear_bit(dlm->node_num, dlm->domain_map); 448 while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES, 449 0)) < O2NM_MAX_NODES) { 450 /* Drop the dlm spinlock. This is safe wrt the domain_map. 451 * -nodes cannot be added now as the 452 * query_join_handlers knows to respond with OK_NO_MAP 453 * -we catch the right network errors if a node is 454 * removed from the map while we're sending him the 455 * exit message. */ 456 spin_unlock(&dlm->spinlock); 457 458 clear_node = 1; 459 460 status = dlm_send_one_domain_exit(dlm, node); 461 if (status < 0 && 462 status != -ENOPROTOOPT && 463 status != -ENOTCONN) { 464 mlog(ML_NOTICE, "Error %d sending domain exit message " 465 "to node %d\n", status, node); 466 467 /* Not sure what to do here but lets sleep for 468 * a bit in case this was a transient 469 * error... */ 470 msleep(DLM_DOMAIN_BACKOFF_MS); 471 clear_node = 0; 472 } 473 474 spin_lock(&dlm->spinlock); 475 /* If we're not clearing the node bit then we intend 476 * to loop back around to try again. */ 477 if (clear_node) 478 clear_bit(node, dlm->domain_map); 479 } 480 spin_unlock(&dlm->spinlock); 481 } 482 483 int dlm_joined(struct dlm_ctxt *dlm) 484 { 485 int ret = 0; 486 487 spin_lock(&dlm_domain_lock); 488 489 if (dlm->dlm_state == DLM_CTXT_JOINED) 490 ret = 1; 491 492 spin_unlock(&dlm_domain_lock); 493 494 return ret; 495 } 496 497 int dlm_shutting_down(struct dlm_ctxt *dlm) 498 { 499 int ret = 0; 500 501 spin_lock(&dlm_domain_lock); 502 503 if (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN) 504 ret = 1; 505 506 spin_unlock(&dlm_domain_lock); 507 508 return ret; 509 } 510 511 void dlm_unregister_domain(struct dlm_ctxt *dlm) 512 { 513 int leave = 0; 514 515 spin_lock(&dlm_domain_lock); 516 BUG_ON(dlm->dlm_state != DLM_CTXT_JOINED); 517 BUG_ON(!dlm->num_joins); 518 519 dlm->num_joins--; 520 if (!dlm->num_joins) { 521 /* We mark it "in shutdown" now so new register 522 * requests wait until we've completely left the 523 * domain. Don't use DLM_CTXT_LEAVING yet as we still 524 * want new domain joins to communicate with us at 525 * least until we've completed migration of our 526 * resources. */ 527 dlm->dlm_state = DLM_CTXT_IN_SHUTDOWN; 528 leave = 1; 529 } 530 spin_unlock(&dlm_domain_lock); 531 532 if (leave) { 533 mlog(0, "shutting down domain %s\n", dlm->name); 534 535 /* We changed dlm state, notify the thread */ 536 dlm_kick_thread(dlm, NULL); 537 538 dlm_migrate_all_locks(dlm); 539 dlm_mark_domain_leaving(dlm); 540 dlm_leave_domain(dlm); 541 dlm_complete_dlm_shutdown(dlm); 542 } 543 dlm_put(dlm); 544 } 545 EXPORT_SYMBOL_GPL(dlm_unregister_domain); 546 547 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data) 548 { 549 struct dlm_query_join_request *query; 550 enum dlm_query_join_response response; 551 struct dlm_ctxt *dlm = NULL; 552 553 query = (struct dlm_query_join_request *) msg->buf; 554 555 mlog(0, "node %u wants to join domain %s\n", query->node_idx, 556 query->domain); 557 558 /* 559 * If heartbeat doesn't consider the node live, tell it 560 * to back off and try again. This gives heartbeat a chance 561 * to catch up. 562 */ 563 if (!o2hb_check_node_heartbeating(query->node_idx)) { 564 mlog(0, "node %u is not in our live map yet\n", 565 query->node_idx); 566 567 response = JOIN_DISALLOW; 568 goto respond; 569 } 570 571 response = JOIN_OK_NO_MAP; 572 573 spin_lock(&dlm_domain_lock); 574 dlm = __dlm_lookup_domain_full(query->domain, query->name_len); 575 /* Once the dlm ctxt is marked as leaving then we don't want 576 * to be put in someone's domain map. 577 * Also, explicitly disallow joining at certain troublesome 578 * times (ie. during recovery). */ 579 if (dlm && dlm->dlm_state != DLM_CTXT_LEAVING) { 580 int bit = query->node_idx; 581 spin_lock(&dlm->spinlock); 582 583 if (dlm->dlm_state == DLM_CTXT_NEW && 584 dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN) { 585 /*If this is a brand new context and we 586 * haven't started our join process yet, then 587 * the other node won the race. */ 588 response = JOIN_OK_NO_MAP; 589 } else if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) { 590 /* Disallow parallel joins. */ 591 response = JOIN_DISALLOW; 592 } else if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) { 593 mlog(ML_NOTICE, "node %u trying to join, but recovery " 594 "is ongoing.\n", bit); 595 response = JOIN_DISALLOW; 596 } else if (test_bit(bit, dlm->recovery_map)) { 597 mlog(ML_NOTICE, "node %u trying to join, but it " 598 "still needs recovery.\n", bit); 599 response = JOIN_DISALLOW; 600 } else if (test_bit(bit, dlm->domain_map)) { 601 mlog(ML_NOTICE, "node %u trying to join, but it " 602 "is still in the domain! needs recovery?\n", 603 bit); 604 response = JOIN_DISALLOW; 605 } else { 606 /* Alright we're fully a part of this domain 607 * so we keep some state as to who's joining 608 * and indicate to him that needs to be fixed 609 * up. */ 610 response = JOIN_OK; 611 __dlm_set_joining_node(dlm, query->node_idx); 612 } 613 614 spin_unlock(&dlm->spinlock); 615 } 616 spin_unlock(&dlm_domain_lock); 617 618 respond: 619 mlog(0, "We respond with %u\n", response); 620 621 return response; 622 } 623 624 static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data) 625 { 626 struct dlm_assert_joined *assert; 627 struct dlm_ctxt *dlm = NULL; 628 629 assert = (struct dlm_assert_joined *) msg->buf; 630 631 mlog(0, "node %u asserts join on domain %s\n", assert->node_idx, 632 assert->domain); 633 634 spin_lock(&dlm_domain_lock); 635 dlm = __dlm_lookup_domain_full(assert->domain, assert->name_len); 636 /* XXX should we consider no dlm ctxt an error? */ 637 if (dlm) { 638 spin_lock(&dlm->spinlock); 639 640 /* Alright, this node has officially joined our 641 * domain. Set him in the map and clean up our 642 * leftover join state. */ 643 BUG_ON(dlm->joining_node != assert->node_idx); 644 set_bit(assert->node_idx, dlm->domain_map); 645 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN); 646 647 __dlm_print_nodes(dlm); 648 649 /* notify anything attached to the heartbeat events */ 650 dlm_hb_event_notify_attached(dlm, assert->node_idx, 1); 651 652 spin_unlock(&dlm->spinlock); 653 } 654 spin_unlock(&dlm_domain_lock); 655 656 return 0; 657 } 658 659 static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data) 660 { 661 struct dlm_cancel_join *cancel; 662 struct dlm_ctxt *dlm = NULL; 663 664 cancel = (struct dlm_cancel_join *) msg->buf; 665 666 mlog(0, "node %u cancels join on domain %s\n", cancel->node_idx, 667 cancel->domain); 668 669 spin_lock(&dlm_domain_lock); 670 dlm = __dlm_lookup_domain_full(cancel->domain, cancel->name_len); 671 672 if (dlm) { 673 spin_lock(&dlm->spinlock); 674 675 /* Yikes, this guy wants to cancel his join. No 676 * problem, we simply cleanup our join state. */ 677 BUG_ON(dlm->joining_node != cancel->node_idx); 678 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN); 679 680 spin_unlock(&dlm->spinlock); 681 } 682 spin_unlock(&dlm_domain_lock); 683 684 return 0; 685 } 686 687 static int dlm_send_one_join_cancel(struct dlm_ctxt *dlm, 688 unsigned int node) 689 { 690 int status; 691 struct dlm_cancel_join cancel_msg; 692 693 memset(&cancel_msg, 0, sizeof(cancel_msg)); 694 cancel_msg.node_idx = dlm->node_num; 695 cancel_msg.name_len = strlen(dlm->name); 696 memcpy(cancel_msg.domain, dlm->name, cancel_msg.name_len); 697 698 status = o2net_send_message(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY, 699 &cancel_msg, sizeof(cancel_msg), node, 700 NULL); 701 if (status < 0) { 702 mlog_errno(status); 703 goto bail; 704 } 705 706 bail: 707 return status; 708 } 709 710 /* map_size should be in bytes. */ 711 static int dlm_send_join_cancels(struct dlm_ctxt *dlm, 712 unsigned long *node_map, 713 unsigned int map_size) 714 { 715 int status, tmpstat; 716 unsigned int node; 717 718 if (map_size != (BITS_TO_LONGS(O2NM_MAX_NODES) * 719 sizeof(unsigned long))) { 720 mlog(ML_ERROR, 721 "map_size %u != BITS_TO_LONGS(O2NM_MAX_NODES) %u\n", 722 map_size, BITS_TO_LONGS(O2NM_MAX_NODES)); 723 return -EINVAL; 724 } 725 726 status = 0; 727 node = -1; 728 while ((node = find_next_bit(node_map, O2NM_MAX_NODES, 729 node + 1)) < O2NM_MAX_NODES) { 730 if (node == dlm->node_num) 731 continue; 732 733 tmpstat = dlm_send_one_join_cancel(dlm, node); 734 if (tmpstat) { 735 mlog(ML_ERROR, "Error return %d cancelling join on " 736 "node %d\n", tmpstat, node); 737 if (!status) 738 status = tmpstat; 739 } 740 } 741 742 if (status) 743 mlog_errno(status); 744 return status; 745 } 746 747 static int dlm_request_join(struct dlm_ctxt *dlm, 748 int node, 749 enum dlm_query_join_response *response) 750 { 751 int status, retval; 752 struct dlm_query_join_request join_msg; 753 754 mlog(0, "querying node %d\n", node); 755 756 memset(&join_msg, 0, sizeof(join_msg)); 757 join_msg.node_idx = dlm->node_num; 758 join_msg.name_len = strlen(dlm->name); 759 memcpy(join_msg.domain, dlm->name, join_msg.name_len); 760 761 status = o2net_send_message(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, &join_msg, 762 sizeof(join_msg), node, &retval); 763 if (status < 0 && status != -ENOPROTOOPT) { 764 mlog_errno(status); 765 goto bail; 766 } 767 768 /* -ENOPROTOOPT from the net code means the other side isn't 769 listening for our message type -- that's fine, it means 770 his dlm isn't up, so we can consider him a 'yes' but not 771 joined into the domain. */ 772 if (status == -ENOPROTOOPT) { 773 status = 0; 774 *response = JOIN_OK_NO_MAP; 775 } else if (retval == JOIN_DISALLOW || 776 retval == JOIN_OK || 777 retval == JOIN_OK_NO_MAP) { 778 *response = retval; 779 } else { 780 status = -EINVAL; 781 mlog(ML_ERROR, "invalid response %d from node %u\n", retval, 782 node); 783 } 784 785 mlog(0, "status %d, node %d response is %d\n", status, node, 786 *response); 787 788 bail: 789 return status; 790 } 791 792 static int dlm_send_one_join_assert(struct dlm_ctxt *dlm, 793 unsigned int node) 794 { 795 int status; 796 struct dlm_assert_joined assert_msg; 797 798 mlog(0, "Sending join assert to node %u\n", node); 799 800 memset(&assert_msg, 0, sizeof(assert_msg)); 801 assert_msg.node_idx = dlm->node_num; 802 assert_msg.name_len = strlen(dlm->name); 803 memcpy(assert_msg.domain, dlm->name, assert_msg.name_len); 804 805 status = o2net_send_message(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY, 806 &assert_msg, sizeof(assert_msg), node, 807 NULL); 808 if (status < 0) 809 mlog_errno(status); 810 811 return status; 812 } 813 814 static void dlm_send_join_asserts(struct dlm_ctxt *dlm, 815 unsigned long *node_map) 816 { 817 int status, node, live; 818 819 status = 0; 820 node = -1; 821 while ((node = find_next_bit(node_map, O2NM_MAX_NODES, 822 node + 1)) < O2NM_MAX_NODES) { 823 if (node == dlm->node_num) 824 continue; 825 826 do { 827 /* It is very important that this message be 828 * received so we spin until either the node 829 * has died or it gets the message. */ 830 status = dlm_send_one_join_assert(dlm, node); 831 832 spin_lock(&dlm->spinlock); 833 live = test_bit(node, dlm->live_nodes_map); 834 spin_unlock(&dlm->spinlock); 835 836 if (status) { 837 mlog(ML_ERROR, "Error return %d asserting " 838 "join on node %d\n", status, node); 839 840 /* give us some time between errors... */ 841 if (live) 842 msleep(DLM_DOMAIN_BACKOFF_MS); 843 } 844 } while (status && live); 845 } 846 } 847 848 struct domain_join_ctxt { 849 unsigned long live_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; 850 unsigned long yes_resp_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; 851 }; 852 853 static int dlm_should_restart_join(struct dlm_ctxt *dlm, 854 struct domain_join_ctxt *ctxt, 855 enum dlm_query_join_response response) 856 { 857 int ret; 858 859 if (response == JOIN_DISALLOW) { 860 mlog(0, "Latest response of disallow -- should restart\n"); 861 return 1; 862 } 863 864 spin_lock(&dlm->spinlock); 865 /* For now, we restart the process if the node maps have 866 * changed at all */ 867 ret = memcmp(ctxt->live_map, dlm->live_nodes_map, 868 sizeof(dlm->live_nodes_map)); 869 spin_unlock(&dlm->spinlock); 870 871 if (ret) 872 mlog(0, "Node maps changed -- should restart\n"); 873 874 return ret; 875 } 876 877 static int dlm_try_to_join_domain(struct dlm_ctxt *dlm) 878 { 879 int status = 0, tmpstat, node; 880 struct domain_join_ctxt *ctxt; 881 enum dlm_query_join_response response; 882 883 mlog_entry("%p", dlm); 884 885 ctxt = kcalloc(1, sizeof(*ctxt), GFP_KERNEL); 886 if (!ctxt) { 887 status = -ENOMEM; 888 mlog_errno(status); 889 goto bail; 890 } 891 892 /* group sem locking should work for us here -- we're already 893 * registered for heartbeat events so filling this should be 894 * atomic wrt getting those handlers called. */ 895 o2hb_fill_node_map(dlm->live_nodes_map, sizeof(dlm->live_nodes_map)); 896 897 spin_lock(&dlm->spinlock); 898 memcpy(ctxt->live_map, dlm->live_nodes_map, sizeof(ctxt->live_map)); 899 900 __dlm_set_joining_node(dlm, dlm->node_num); 901 902 spin_unlock(&dlm->spinlock); 903 904 node = -1; 905 while ((node = find_next_bit(ctxt->live_map, O2NM_MAX_NODES, 906 node + 1)) < O2NM_MAX_NODES) { 907 if (node == dlm->node_num) 908 continue; 909 910 status = dlm_request_join(dlm, node, &response); 911 if (status < 0) { 912 mlog_errno(status); 913 goto bail; 914 } 915 916 /* Ok, either we got a response or the node doesn't have a 917 * dlm up. */ 918 if (response == JOIN_OK) 919 set_bit(node, ctxt->yes_resp_map); 920 921 if (dlm_should_restart_join(dlm, ctxt, response)) { 922 status = -EAGAIN; 923 goto bail; 924 } 925 } 926 927 mlog(0, "Yay, done querying nodes!\n"); 928 929 /* Yay, everyone agree's we can join the domain. My domain is 930 * comprised of all nodes who were put in the 931 * yes_resp_map. Copy that into our domain map and send a join 932 * assert message to clean up everyone elses state. */ 933 spin_lock(&dlm->spinlock); 934 memcpy(dlm->domain_map, ctxt->yes_resp_map, 935 sizeof(ctxt->yes_resp_map)); 936 set_bit(dlm->node_num, dlm->domain_map); 937 spin_unlock(&dlm->spinlock); 938 939 dlm_send_join_asserts(dlm, ctxt->yes_resp_map); 940 941 /* Joined state *must* be set before the joining node 942 * information, otherwise the query_join handler may read no 943 * current joiner but a state of NEW and tell joining nodes 944 * we're not in the domain. */ 945 spin_lock(&dlm_domain_lock); 946 dlm->dlm_state = DLM_CTXT_JOINED; 947 dlm->num_joins++; 948 spin_unlock(&dlm_domain_lock); 949 950 bail: 951 spin_lock(&dlm->spinlock); 952 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN); 953 if (!status) 954 __dlm_print_nodes(dlm); 955 spin_unlock(&dlm->spinlock); 956 957 if (ctxt) { 958 /* Do we need to send a cancel message to any nodes? */ 959 if (status < 0) { 960 tmpstat = dlm_send_join_cancels(dlm, 961 ctxt->yes_resp_map, 962 sizeof(ctxt->yes_resp_map)); 963 if (tmpstat < 0) 964 mlog_errno(tmpstat); 965 } 966 kfree(ctxt); 967 } 968 969 mlog(0, "returning %d\n", status); 970 return status; 971 } 972 973 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm) 974 { 975 o2hb_unregister_callback(&dlm->dlm_hb_up); 976 o2hb_unregister_callback(&dlm->dlm_hb_down); 977 o2net_unregister_handler_list(&dlm->dlm_domain_handlers); 978 } 979 980 static int dlm_register_domain_handlers(struct dlm_ctxt *dlm) 981 { 982 int status; 983 984 mlog(0, "registering handlers.\n"); 985 986 o2hb_setup_callback(&dlm->dlm_hb_down, O2HB_NODE_DOWN_CB, 987 dlm_hb_node_down_cb, dlm, DLM_HB_NODE_DOWN_PRI); 988 status = o2hb_register_callback(&dlm->dlm_hb_down); 989 if (status) 990 goto bail; 991 992 o2hb_setup_callback(&dlm->dlm_hb_up, O2HB_NODE_UP_CB, 993 dlm_hb_node_up_cb, dlm, DLM_HB_NODE_UP_PRI); 994 status = o2hb_register_callback(&dlm->dlm_hb_up); 995 if (status) 996 goto bail; 997 998 status = o2net_register_handler(DLM_MASTER_REQUEST_MSG, dlm->key, 999 sizeof(struct dlm_master_request), 1000 dlm_master_request_handler, 1001 dlm, &dlm->dlm_domain_handlers); 1002 if (status) 1003 goto bail; 1004 1005 status = o2net_register_handler(DLM_ASSERT_MASTER_MSG, dlm->key, 1006 sizeof(struct dlm_assert_master), 1007 dlm_assert_master_handler, 1008 dlm, &dlm->dlm_domain_handlers); 1009 if (status) 1010 goto bail; 1011 1012 status = o2net_register_handler(DLM_CREATE_LOCK_MSG, dlm->key, 1013 sizeof(struct dlm_create_lock), 1014 dlm_create_lock_handler, 1015 dlm, &dlm->dlm_domain_handlers); 1016 if (status) 1017 goto bail; 1018 1019 status = o2net_register_handler(DLM_CONVERT_LOCK_MSG, dlm->key, 1020 DLM_CONVERT_LOCK_MAX_LEN, 1021 dlm_convert_lock_handler, 1022 dlm, &dlm->dlm_domain_handlers); 1023 if (status) 1024 goto bail; 1025 1026 status = o2net_register_handler(DLM_UNLOCK_LOCK_MSG, dlm->key, 1027 DLM_UNLOCK_LOCK_MAX_LEN, 1028 dlm_unlock_lock_handler, 1029 dlm, &dlm->dlm_domain_handlers); 1030 if (status) 1031 goto bail; 1032 1033 status = o2net_register_handler(DLM_PROXY_AST_MSG, dlm->key, 1034 DLM_PROXY_AST_MAX_LEN, 1035 dlm_proxy_ast_handler, 1036 dlm, &dlm->dlm_domain_handlers); 1037 if (status) 1038 goto bail; 1039 1040 status = o2net_register_handler(DLM_EXIT_DOMAIN_MSG, dlm->key, 1041 sizeof(struct dlm_exit_domain), 1042 dlm_exit_domain_handler, 1043 dlm, &dlm->dlm_domain_handlers); 1044 if (status) 1045 goto bail; 1046 1047 status = o2net_register_handler(DLM_MIGRATE_REQUEST_MSG, dlm->key, 1048 sizeof(struct dlm_migrate_request), 1049 dlm_migrate_request_handler, 1050 dlm, &dlm->dlm_domain_handlers); 1051 if (status) 1052 goto bail; 1053 1054 status = o2net_register_handler(DLM_MIG_LOCKRES_MSG, dlm->key, 1055 DLM_MIG_LOCKRES_MAX_LEN, 1056 dlm_mig_lockres_handler, 1057 dlm, &dlm->dlm_domain_handlers); 1058 if (status) 1059 goto bail; 1060 1061 status = o2net_register_handler(DLM_MASTER_REQUERY_MSG, dlm->key, 1062 sizeof(struct dlm_master_requery), 1063 dlm_master_requery_handler, 1064 dlm, &dlm->dlm_domain_handlers); 1065 if (status) 1066 goto bail; 1067 1068 status = o2net_register_handler(DLM_LOCK_REQUEST_MSG, dlm->key, 1069 sizeof(struct dlm_lock_request), 1070 dlm_request_all_locks_handler, 1071 dlm, &dlm->dlm_domain_handlers); 1072 if (status) 1073 goto bail; 1074 1075 status = o2net_register_handler(DLM_RECO_DATA_DONE_MSG, dlm->key, 1076 sizeof(struct dlm_reco_data_done), 1077 dlm_reco_data_done_handler, 1078 dlm, &dlm->dlm_domain_handlers); 1079 if (status) 1080 goto bail; 1081 1082 status = o2net_register_handler(DLM_BEGIN_RECO_MSG, dlm->key, 1083 sizeof(struct dlm_begin_reco), 1084 dlm_begin_reco_handler, 1085 dlm, &dlm->dlm_domain_handlers); 1086 if (status) 1087 goto bail; 1088 1089 status = o2net_register_handler(DLM_FINALIZE_RECO_MSG, dlm->key, 1090 sizeof(struct dlm_finalize_reco), 1091 dlm_finalize_reco_handler, 1092 dlm, &dlm->dlm_domain_handlers); 1093 if (status) 1094 goto bail; 1095 1096 bail: 1097 if (status) 1098 dlm_unregister_domain_handlers(dlm); 1099 1100 return status; 1101 } 1102 1103 static int dlm_join_domain(struct dlm_ctxt *dlm) 1104 { 1105 int status; 1106 1107 BUG_ON(!dlm); 1108 1109 mlog(0, "Join domain %s\n", dlm->name); 1110 1111 status = dlm_register_domain_handlers(dlm); 1112 if (status) { 1113 mlog_errno(status); 1114 goto bail; 1115 } 1116 1117 status = dlm_launch_thread(dlm); 1118 if (status < 0) { 1119 mlog_errno(status); 1120 goto bail; 1121 } 1122 1123 status = dlm_launch_recovery_thread(dlm); 1124 if (status < 0) { 1125 mlog_errno(status); 1126 goto bail; 1127 } 1128 1129 do { 1130 unsigned int backoff; 1131 status = dlm_try_to_join_domain(dlm); 1132 1133 /* If we're racing another node to the join, then we 1134 * need to back off temporarily and let them 1135 * complete. */ 1136 if (status == -EAGAIN) { 1137 if (signal_pending(current)) { 1138 status = -ERESTARTSYS; 1139 goto bail; 1140 } 1141 1142 /* 1143 * <chip> After you! 1144 * <dale> No, after you! 1145 * <chip> I insist! 1146 * <dale> But you first! 1147 * ... 1148 */ 1149 backoff = (unsigned int)(jiffies & 0x3); 1150 backoff *= DLM_DOMAIN_BACKOFF_MS; 1151 mlog(0, "backoff %d\n", backoff); 1152 msleep(backoff); 1153 } 1154 } while (status == -EAGAIN); 1155 1156 if (status < 0) { 1157 mlog_errno(status); 1158 goto bail; 1159 } 1160 1161 status = 0; 1162 bail: 1163 wake_up(&dlm_domain_events); 1164 1165 if (status) { 1166 dlm_unregister_domain_handlers(dlm); 1167 dlm_complete_thread(dlm); 1168 dlm_complete_recovery_thread(dlm); 1169 } 1170 1171 return status; 1172 } 1173 1174 static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain, 1175 u32 key) 1176 { 1177 int i; 1178 struct dlm_ctxt *dlm = NULL; 1179 1180 dlm = kcalloc(1, sizeof(*dlm), GFP_KERNEL); 1181 if (!dlm) { 1182 mlog_errno(-ENOMEM); 1183 goto leave; 1184 } 1185 1186 dlm->name = kmalloc(strlen(domain) + 1, GFP_KERNEL); 1187 if (dlm->name == NULL) { 1188 mlog_errno(-ENOMEM); 1189 kfree(dlm); 1190 dlm = NULL; 1191 goto leave; 1192 } 1193 1194 dlm->lockres_hash = (struct hlist_head *) __get_free_page(GFP_KERNEL); 1195 if (!dlm->lockres_hash) { 1196 mlog_errno(-ENOMEM); 1197 kfree(dlm->name); 1198 kfree(dlm); 1199 dlm = NULL; 1200 goto leave; 1201 } 1202 1203 for (i=0; i<DLM_HASH_BUCKETS; i++) 1204 INIT_HLIST_HEAD(&dlm->lockres_hash[i]); 1205 1206 strcpy(dlm->name, domain); 1207 dlm->key = key; 1208 dlm->node_num = o2nm_this_node(); 1209 1210 spin_lock_init(&dlm->spinlock); 1211 spin_lock_init(&dlm->master_lock); 1212 spin_lock_init(&dlm->ast_lock); 1213 INIT_LIST_HEAD(&dlm->list); 1214 INIT_LIST_HEAD(&dlm->dirty_list); 1215 INIT_LIST_HEAD(&dlm->reco.resources); 1216 INIT_LIST_HEAD(&dlm->reco.received); 1217 INIT_LIST_HEAD(&dlm->reco.node_data); 1218 INIT_LIST_HEAD(&dlm->purge_list); 1219 INIT_LIST_HEAD(&dlm->dlm_domain_handlers); 1220 dlm->reco.state = 0; 1221 1222 INIT_LIST_HEAD(&dlm->pending_asts); 1223 INIT_LIST_HEAD(&dlm->pending_basts); 1224 1225 mlog(0, "dlm->recovery_map=%p, &(dlm->recovery_map[0])=%p\n", 1226 dlm->recovery_map, &(dlm->recovery_map[0])); 1227 1228 memset(dlm->recovery_map, 0, sizeof(dlm->recovery_map)); 1229 memset(dlm->live_nodes_map, 0, sizeof(dlm->live_nodes_map)); 1230 memset(dlm->domain_map, 0, sizeof(dlm->domain_map)); 1231 1232 dlm->dlm_thread_task = NULL; 1233 dlm->dlm_reco_thread_task = NULL; 1234 init_waitqueue_head(&dlm->dlm_thread_wq); 1235 init_waitqueue_head(&dlm->dlm_reco_thread_wq); 1236 init_waitqueue_head(&dlm->reco.event); 1237 init_waitqueue_head(&dlm->ast_wq); 1238 init_waitqueue_head(&dlm->migration_wq); 1239 INIT_LIST_HEAD(&dlm->master_list); 1240 INIT_LIST_HEAD(&dlm->mle_hb_events); 1241 1242 dlm->joining_node = DLM_LOCK_RES_OWNER_UNKNOWN; 1243 init_waitqueue_head(&dlm->dlm_join_events); 1244 1245 dlm->reco.new_master = O2NM_INVALID_NODE_NUM; 1246 dlm->reco.dead_node = O2NM_INVALID_NODE_NUM; 1247 atomic_set(&dlm->local_resources, 0); 1248 atomic_set(&dlm->remote_resources, 0); 1249 atomic_set(&dlm->unknown_resources, 0); 1250 1251 spin_lock_init(&dlm->work_lock); 1252 INIT_LIST_HEAD(&dlm->work_list); 1253 INIT_WORK(&dlm->dispatched_work, dlm_dispatch_work, dlm); 1254 1255 kref_init(&dlm->dlm_refs); 1256 dlm->dlm_state = DLM_CTXT_NEW; 1257 1258 INIT_LIST_HEAD(&dlm->dlm_eviction_callbacks); 1259 1260 mlog(0, "context init: refcount %u\n", 1261 atomic_read(&dlm->dlm_refs.refcount)); 1262 1263 leave: 1264 return dlm; 1265 } 1266 1267 /* 1268 * dlm_register_domain: one-time setup per "domain" 1269 */ 1270 struct dlm_ctxt * dlm_register_domain(const char *domain, 1271 u32 key) 1272 { 1273 int ret; 1274 struct dlm_ctxt *dlm = NULL; 1275 struct dlm_ctxt *new_ctxt = NULL; 1276 1277 if (strlen(domain) > O2NM_MAX_NAME_LEN) { 1278 ret = -ENAMETOOLONG; 1279 mlog(ML_ERROR, "domain name length too long\n"); 1280 goto leave; 1281 } 1282 1283 if (!o2hb_check_local_node_heartbeating()) { 1284 mlog(ML_ERROR, "the local node has not been configured, or is " 1285 "not heartbeating\n"); 1286 ret = -EPROTO; 1287 goto leave; 1288 } 1289 1290 mlog(0, "register called for domain \"%s\"\n", domain); 1291 1292 retry: 1293 dlm = NULL; 1294 if (signal_pending(current)) { 1295 ret = -ERESTARTSYS; 1296 mlog_errno(ret); 1297 goto leave; 1298 } 1299 1300 spin_lock(&dlm_domain_lock); 1301 1302 dlm = __dlm_lookup_domain(domain); 1303 if (dlm) { 1304 if (dlm->dlm_state != DLM_CTXT_JOINED) { 1305 spin_unlock(&dlm_domain_lock); 1306 1307 mlog(0, "This ctxt is not joined yet!\n"); 1308 wait_event_interruptible(dlm_domain_events, 1309 dlm_wait_on_domain_helper( 1310 domain)); 1311 goto retry; 1312 } 1313 1314 __dlm_get(dlm); 1315 dlm->num_joins++; 1316 1317 spin_unlock(&dlm_domain_lock); 1318 1319 ret = 0; 1320 goto leave; 1321 } 1322 1323 /* doesn't exist */ 1324 if (!new_ctxt) { 1325 spin_unlock(&dlm_domain_lock); 1326 1327 new_ctxt = dlm_alloc_ctxt(domain, key); 1328 if (new_ctxt) 1329 goto retry; 1330 1331 ret = -ENOMEM; 1332 mlog_errno(ret); 1333 goto leave; 1334 } 1335 1336 /* a little variable switch-a-roo here... */ 1337 dlm = new_ctxt; 1338 new_ctxt = NULL; 1339 1340 /* add the new domain */ 1341 list_add_tail(&dlm->list, &dlm_domains); 1342 spin_unlock(&dlm_domain_lock); 1343 1344 ret = dlm_join_domain(dlm); 1345 if (ret) { 1346 mlog_errno(ret); 1347 dlm_put(dlm); 1348 goto leave; 1349 } 1350 1351 ret = 0; 1352 leave: 1353 if (new_ctxt) 1354 dlm_free_ctxt_mem(new_ctxt); 1355 1356 if (ret < 0) 1357 dlm = ERR_PTR(ret); 1358 1359 return dlm; 1360 } 1361 EXPORT_SYMBOL_GPL(dlm_register_domain); 1362 1363 static LIST_HEAD(dlm_join_handlers); 1364 1365 static void dlm_unregister_net_handlers(void) 1366 { 1367 o2net_unregister_handler_list(&dlm_join_handlers); 1368 } 1369 1370 static int dlm_register_net_handlers(void) 1371 { 1372 int status = 0; 1373 1374 status = o2net_register_handler(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, 1375 sizeof(struct dlm_query_join_request), 1376 dlm_query_join_handler, 1377 NULL, &dlm_join_handlers); 1378 if (status) 1379 goto bail; 1380 1381 status = o2net_register_handler(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY, 1382 sizeof(struct dlm_assert_joined), 1383 dlm_assert_joined_handler, 1384 NULL, &dlm_join_handlers); 1385 if (status) 1386 goto bail; 1387 1388 status = o2net_register_handler(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY, 1389 sizeof(struct dlm_cancel_join), 1390 dlm_cancel_join_handler, 1391 NULL, &dlm_join_handlers); 1392 1393 bail: 1394 if (status < 0) 1395 dlm_unregister_net_handlers(); 1396 1397 return status; 1398 } 1399 1400 /* Domain eviction callback handling. 1401 * 1402 * The file system requires notification of node death *before* the 1403 * dlm completes it's recovery work, otherwise it may be able to 1404 * acquire locks on resources requiring recovery. Since the dlm can 1405 * evict a node from it's domain *before* heartbeat fires, a similar 1406 * mechanism is required. */ 1407 1408 /* Eviction is not expected to happen often, so a per-domain lock is 1409 * not necessary. Eviction callbacks are allowed to sleep for short 1410 * periods of time. */ 1411 static DECLARE_RWSEM(dlm_callback_sem); 1412 1413 void dlm_fire_domain_eviction_callbacks(struct dlm_ctxt *dlm, 1414 int node_num) 1415 { 1416 struct list_head *iter; 1417 struct dlm_eviction_cb *cb; 1418 1419 down_read(&dlm_callback_sem); 1420 list_for_each(iter, &dlm->dlm_eviction_callbacks) { 1421 cb = list_entry(iter, struct dlm_eviction_cb, ec_item); 1422 1423 cb->ec_func(node_num, cb->ec_data); 1424 } 1425 up_read(&dlm_callback_sem); 1426 } 1427 1428 void dlm_setup_eviction_cb(struct dlm_eviction_cb *cb, 1429 dlm_eviction_func *f, 1430 void *data) 1431 { 1432 INIT_LIST_HEAD(&cb->ec_item); 1433 cb->ec_func = f; 1434 cb->ec_data = data; 1435 } 1436 EXPORT_SYMBOL_GPL(dlm_setup_eviction_cb); 1437 1438 void dlm_register_eviction_cb(struct dlm_ctxt *dlm, 1439 struct dlm_eviction_cb *cb) 1440 { 1441 down_write(&dlm_callback_sem); 1442 list_add_tail(&cb->ec_item, &dlm->dlm_eviction_callbacks); 1443 up_write(&dlm_callback_sem); 1444 } 1445 EXPORT_SYMBOL_GPL(dlm_register_eviction_cb); 1446 1447 void dlm_unregister_eviction_cb(struct dlm_eviction_cb *cb) 1448 { 1449 down_write(&dlm_callback_sem); 1450 list_del_init(&cb->ec_item); 1451 up_write(&dlm_callback_sem); 1452 } 1453 EXPORT_SYMBOL_GPL(dlm_unregister_eviction_cb); 1454 1455 static int __init dlm_init(void) 1456 { 1457 int status; 1458 1459 dlm_print_version(); 1460 1461 status = dlm_init_mle_cache(); 1462 if (status) 1463 return -1; 1464 1465 status = dlm_register_net_handlers(); 1466 if (status) { 1467 dlm_destroy_mle_cache(); 1468 return -1; 1469 } 1470 1471 return 0; 1472 } 1473 1474 static void __exit dlm_exit (void) 1475 { 1476 dlm_unregister_net_handlers(); 1477 dlm_destroy_mle_cache(); 1478 } 1479 1480 MODULE_AUTHOR("Oracle"); 1481 MODULE_LICENSE("GPL"); 1482 1483 module_init(dlm_init); 1484 module_exit(dlm_exit); 1485